A restaurant in Zhengzhou, Henan province, offers a free meal to 50 customers who score top marks in looks every day from Jan 10 to Feb 9. Customers have to scan their faces and then are judged by staff of a plastic surgery clinic. Customers are grouped together after every half hour. The five with top marks in the group get a free meal.

How long will the event last?

A. half a month

B. from Jan 9 to Feb 9

C. one month

（中国日报网英语点津 Helen 编辑）